Adding second 680 Lightning! 650W enough?

tokyoduong;
I cannot take the min power requirement seriously. I think some manufacturers account for people with really crappy PSU(low amp 12V lines). My 7850 came with a recommendation of 500w psu and I'm running a 430W without any problems.[/QUOTE said:

And when your PSU dies and takes out the CPU memory mainboard and the GPU. You can only blame you, the PSU is the most important part of a computer. So if you cook a complete system with some $40 PSU you will then learn what they are saying...............

2 x 7970's and a core i7 3770K at 4.7GHz and the 7970's at 1200/1600 overvolted draw about 720 watts at full load...... 680's draw less thus a good quality 750Watt PSU will easily do thew trick. Now your asking someone in to chime in on recommendations and your blindly suggesting a 850 watt. Just saying.... I have no Idea where 1050 watt is coming in for 2 x 680's?????? I guess we could keep throwing blind suggestions against the wall....

I didn't blindly say anything about him needing a 1050w psu.. I said I would buy the AX1050w psu.. I never said he needs to buy. I told him I wouldn't buy anything below a 850w PSU when he asked about an 850w PSU. He has factory overclocked lighting cards that he wants to overclock higher. At this point you are the only one throwing blind suggestions.. I think in the end you just have issues with me being right, and that's a well sighted fact, and not suggestion.

And when your PSU dies and takes out the CPU memory mainboard and the GPU. You can only blame you, the PSU is the most important part of a computer. So if you cook a complete system with some $40 PSU you will then learn what they are saying...............

Click to expand...

Its true though. $40 PSUs can be perfectly good for low power systems.

I didn't blindly say anything about him needing a 1050w psu.. I said I would buy the AX1050w psu.. I never said he needs to buy. I told him I wouldn't buy anything below a 850w PSU when he asked about an 850w PSU. He has factory overclocked lighting cards that he wants to overclock higher. At this point you are the only one throwing blind suggestions.. I think in the end you just have issues with me being right, and that's a well sighted fact, and not suggestion.

Click to expand...

Ummm Nope, no blind suggestions here. I put the chart up and Erocker put 53 amps. Read up. 750 Watt would be more than enough. TX 750 has a 62 Amp rail and plenty of horsepower.... I think the thread is now totally covered. No need to try to flex anything else. You are NOT right. The cards overclocked in his system plus his CPU overclocked will not need anything more than a TX750. Appreciate your guess though. Heck, if you read earlier, you would see that I have 2 x 7970's and tested a 3770K at 4.7GHz with 2 x 7970's at 1200/1600 overvolted and the system drew 720 watts with a watt o meter used to check. 680's do not draw nearly as much as 2 7970's but I suppose you will keep arguing the point.....

Ummm Nope, no blind suggestions here. I put the chart up and Erocker put 53 amps. Read up. 750 Watt would be more than enough. TX 750 has a 62 Amp rail and plenty of horsepower.... I think the thread is now totally covered. No need to try to flex anything else. You are NOT right. The cards overclocked in his system plus his CPU overclocked will not need anything more than a TX750. Appreciate your guess though. Heck, if you read earlier, you would see that I have 2 x 7970's and tested a 3770K at 4.7GHz with 2 x 7970's at 1200/1600 overvolted and the system drew 720 watts with a watt o meter used to check. 680's do not draw nearly as much as 2 7970's but I suppose you will keep arguing the point.....

Click to expand...

Wow, you really do have issues.. How is me telling him what I would buy, be wrong? How is that even a right or wrong answer? You are still going on, and on about your testing of completely 2 different cards.. Again, I would still buy a AX1050 if I bought 2x GTX680.. Why? Because like I said He is an overclocker and might need the room later.. Someone buying 2x GTX680's sounds like a person that may keep adding to his system.. If he has to buy a new powersupply any way, why not get something better now? Why do you have an 1100w PSU? By what you are saying you should have bought a 950w psu.. Oh wait you have water cooling... Oh he'll never want to water cool? or will he? Well not if he buys a 750w psu.. Hell what if he wants to buy another GTX680 and tri sli? Oh wait if he listens to you he'll have to get another psu... Obviously he wants to sink some money into his rig.. So, why on earth would you suggest a 750w psu.. Oh wait you said at first he would probably be fine with a 650w PSU.. lol (that's your LOL not mine.. lol <---that's mine)

If he came in here with a 750w PSU it would be a different thing all together, but he didn't he came in with a 650w PSU.. So, why keep telling him to get a 750w PSU.. All I'm suggesting him to do is get something his system can grow with.. Future proof it.. I believe erocker would agree to get a bigger PSU and so would most of the users here at TPU that are overclockers. Simply because erocker is using a 1kw psu, and you are using a 1100w..

i was running a 2500k + 2x 6970s and managed to blow up an HX 850 because I overloaded the smaller 3.3v and 5v rails with to many HDDs

I am willing to run the risk myself but thats generally in single GPU systems

and heres why yes at the wall with typical load you will be fine, but when you start benching to test stability for GPUs CPUs etc and put the system to the test your gonna peak far higher than that so called average.

Take it from someone that earned the name "Chief Broken Rig"

I had lightning fry a 4870x2 and a 790gx board
I had a corsair HX 850 die from the minor rails being two weak killing 2x 6970s and 3x HDDs

get yourself a god damn proper PSU before splurging on a $500 graphic card serious.

$1000 in gpu and your gonna risk it on a entry level unit?

thats like having unprotected sex with a hooker. Your playing Russian roulette here.

A decent 750w would be the minimum for maximum efficiency an 850w would be ideal.

When using WCG and F@H its possible to hit 550w give or take,

people always forget the smaller things that draw power, SSD, HDD, Optical, Fans, etc etc an HDD at bootup will peak around 25w I happen to have 5 of them so I MUST use staggered spinup just for my system to boot and thats on a 1000w unit.

550w add in extra's your gonna be closer to 600w nearly red lining the TX650 a 750 again is the minimum i would trust to get the job done, but an 850 offers the best curve as typical gaming you will be closer to 400-450w which puts you at 50% and thus highest efficency.

You know the simplest thing to do would be just try it and if it doesn't work get the bigger psu. It's highly unlikely it would damage anything to try the 650.

Click to expand...

Why do you think people are here arguing? Bacause it can do damage, and it can take out other parts if its not up to snuff.
Im not here to argue or be right, let me ask you this would you put in a cheap pace maker if your heart has trouble? Why wouldnt you, oh cause its your heart!!! Well so is the PSU..............nuff said go ahead have the last word.

Why do you think people are here arguing? Bacause it can do damage, and it can take out other parts if its not up to snuff.
Im not here to argue or be right, let me ask you this would you put in a cheap pace maker if your heart has trouble? Why wouldnt you, oh cause its your heart!!! Well so is the PSU..............nuff said go ahead have the last word.

Click to expand...

Because over the millions of PSU's sold, some have to bring out isolated instances. The math does not lie on how many watts a system draw. Pushing a PSU to it's limits is indeed not recommended, but 2 x 680's and a 3770K will pull 600-650 watts or so. I have not heard TX750's blowing their 3 or 5 volt rail so now we are in uncharted territory. The math does not lie. Anything over 750 watt is overkill and not needed plus a PSU runs more efficient at 90% than 50%. Comparing a PSU to a pace maker is NOT apples to apples my friend...

Im not here to argue or be right, let me ask you this would you put in a cheap pace maker if your heart has trouble? Why wouldnt you, oh cause its your heart!!! Well so is the PSU..............nuff said go ahead have the last word.

Click to expand...

Again, what is up with you talking like the TX is some bargain unit. If you want to argue about the wattage ok but nobody here is preaching for using crap power supplies. That's a completely different discussion.

Again, what is up with you talking like the TX is some bargain unit. If you want to argue about the wattage ok but nobody here is preaching for using crap power supplies. That's a completely different discussion.

Click to expand...

I never mentioned the TX, you jumped in on me. Dont put words in my mouth I didnt say, read up dude was talking about a $40 PSU thats what I was talking about (is this the ADD section of the forum?). Seriuosly Read what i was saying I was talking to that dude and the OP, you jumped in without reading!
I have a TX why would knock it? I was making a point about cheap PSU, and yes they usually dont chit the bed but rather die slowly. With $1000 of GPU'S id suggest to THE OP to buy a beefer unit.......
Medication time!

Not offering any recommendation, just something based off my own experience. I had built my rig mainly for dual HD7970, and I had picked the LGA2011 platform for my build. With OCing in mind and having a 3960X + 2x HD7970, the Corsair HX1050 was the logical choice. It performed admirably, allowing me to hit 4.7ghz on my CPU, and 1100/1450 on my GPUs, it hardly broke a sweat actually. So, a HX1050 for 2xGTX680's should not be a problem at all, the PSU would hardly break a sweat. Now, why am I so certain? Simple, the HX1050 even handled 3x HD7970 when I upped my GPU's with a third card. It ran my system stably, but I would be first to admit that I was pretty antsy about it. The fact that the air vented from the PSU was a fair bit warmer than with two cards served to only exascerbate matters.

Although the HX1050 seemed to be handling the three cards well enough, I couldn't shake this nagging doubt. After a couple of weeks or so, I decided to put the matter to rest by swapping out the HX1050 with a Seasonic X-1250. After that, I was able to sleep well without worrying about my PSU crapping on me whenever I powered up my main rig.

As for OP, that 650W PSU is cutting it pretty close, and since you can afford an expensive card like the GTX680, why cheap out on PSU? Look at me, I buy the best I can afford, and I never go cheap on the most important component in a system.....the PSU. My HX1050 is not being idle either, I swapped my Seasonic SS-850AT Bronze PSU with it, it is now powering my 2nd rig in my sig. The SS-850AT is now my backup PSU.....

Not offering any recommendation, just something based off my own experience. I had built my rig mainly for dual HD7970, and I had picked the LGA2011 platform for my build. With OCing in mind and having a 3960X + 2x HD7970, the Corsair HX1050 was the logical choice. It performed admirably, allowing me to hit 4.7ghz on my CPU, and 1100/1450 on my GPUs, it hardly broke a sweat actually. So, a HX1050 for 2xGTX680's should not be a problem at all, the PSU would hardly break a sweat. Now, why am I so certain? Simple, the HX1050 even handled 3x HD7970 when I upped my GPU's with a third card. It ran my system stably, but I would be first to admit that I was pretty antsy about it. The fact that the air vented from the PSU was a fair bit warmer than with two cards served to only exascerbate matters.

Although the HX1050 seemed to be handling the three cards well enough, I couldn't shake this nagging doubt. After a couple of weeks or so, I decided to put the matter to rest by swapping out the HX1050 with a Seasonic X-1250. After that, I was able to sleep well without worrying about my PSU crapping on me whenever I powered up my main rig.

As for OP, that 650W PSU is cutting it pretty close, and since you can afford an expensive card like the GTX680, why cheap out on PSU? Look at me, I buy the best I can afford, and I never go cheap on the most important component in a system.....the PSU. My HX1050 is not being idle either, I swapped my Seasonic SS-850AT Bronze PSU with it, it is now powering my 2nd rig in my sig. The SS-850AT is now my backup PSU.....

Click to expand...

Your rig highly overclocked with 3 x 7970's overclocked will pull over 1000 watts under full load....so you cut your close too. I actually took a 3770K and 3 x 7970's and the watt o meter hit 1080 watts under 100% load. Your CPU will use more power than IvyBridge so be careful.

It's OK, I have the X-1250, I am quite confident it can handle the load. Btw, when I had the HX1050 in my main rig, I did not OC......much, I do recall having my CPU @4.25ghz with the three cards @1050/1425......no problemo. The HX1050 is one solid PSU, I figured that if it can handle my rig with mild OCs, the X-1250 would allow for more OCs and such.

It's OK, I have the X-1250, I am quite confident it can handle the load. Btw, when I had the HX1050 in my main rig, I did not OC......much, I do recall having my CPU @4.25ghz with the three cards @1050/1425......no problemo. The HX1050 is one solid PSU, I figured that if it can handle my rig with mild OCs, the X-1250 would allow for more OCs and such.

Click to expand...

Ohh your good to go. Just sayin I was surprised at how much the draw was.

You know, it's easy to draw a lot of power when you start overclocking. At stock my rig won't break 350-400 watts fully loaded. If I overclock it that number becomes more like 550-600 fully loaded, which isn't always realistic when you're gaming but it describes the upper bound of how hard your machine is going to work. I have two 6870 and it's really easy to make them eat more power and they're more than happy to take more voltage.

I guess the real point I'm trying to make it one that drdeathx had made before, get yourself a Kill-A-Watt or something else that lets you measure your power consumption. It's something worth having imho.